Question

Question 3


A pair of equations is shown below:

y = 7x − 8
y = 5x − 2

Part A: Explain how you will solve the pair of equations by substitution or elimination. Show all the steps and write the solution. (5 points)

Part B: If the two equations are graphed, at what point will the lines representing the two equations intersect? Explain your answer. (5 points)

Answer 1

A) Substitution
substitute y = 5x-2 for y in the first equation and solve for x:
5x-2 = 7x-8 subtract 7x from both sides
-2x-2 = -8 now add 2 to both sides
-2x = -8 + 2 simplify
-2x = -6 divide both sides by -2
x=3
Now substitute x with 3 in either equation
y=5x-2 =5*3-2 =13 
(3,13)
B) (3,13) is the point where the two lines intersect
y=mx+b is the equation of a line